What are the new features observed in 20.4 Version?

The docs are your friends....

docs.appian.com/.../Appian_Release_Notes.html

We also provide the Release Showcase, which teaches experienced practitioners more about the features in each release and how to leverage them in your application development. You can access this quarterly release training from Academy Online. Here's a direct link to the 20.4 course: 20.4 Release Showcase.

Hi [mention:9a47e4e889564c919494c016f6db43b8:e9ed411860ed4f2ba0265705b8793d05],

We also provide a free, quarterly webinar that aligns with our product release schedule. The webinar highlights all the new features. 

community.appian.com/.../appian-20-4-product-announcement-webinar